Forsling M L, Williams H
J Physiol. 1984 Jan;346:49-59. doi: 10.1113/jphysiol.1984.sp015006.
The effect of intracerebroventricular (I.C.V.) micro-injections of dopamine on vasopressin (AVP) release was investigated in normally hydrated and hydrated rats anaesthetized with urethane, hormone concentrations being determined by radioimmunoassay. Dopamine given in doses of less than 25 micrograms had little effect on AVP concentrations already elevated as a result of anaesthesia and surgery. Doses of over 25 micrograms produced a transient increase in AVP concentrations followed by a fall. Both the increase and the fall were statistically significant. Pimozide (400 micrograms/kg) blocked the fall in AVP concentrations following dopamine. A fall was still seen after the administration of haloperidol (400 micrograms/kg) but it was only significant 20 min after the injection of dopamine. The changes in AVP concentration after the administration of naloxone (400 micrograms/kg) were not statistically significant. In water-loaded rats I.C.V. micro-injections of dopamine produced a dose-dependent antidiuresis over the range 1-25 micrograms. An injection of 25 micrograms dopamine in these animals produced an increase in AVP concentrations to 1.8 +/- 0.51 microunits/ml and a fall in urine flow which could be approximately matched by an infusion of vasopressin of 15 microunits/min. The antidiuresis in response to dopamine could be blocked by haloperidol. The response to dopamine in the anaesthetized animals depends on a number of factors including the initial activity of the neurohypophysial system.
在以乌拉坦麻醉的正常水合和水负荷大鼠中，研究了脑室内（I.C.V.）微量注射多巴胺对血管加压素（AVP）释放的影响，通过放射免疫测定法测定激素浓度。剂量小于25微克的多巴胺对因麻醉和手术而已经升高的AVP浓度影响很小。超过25微克的剂量会使AVP浓度短暂升高，随后下降。升高和下降在统计学上均有显著意义。匹莫齐特（400微克/千克）可阻断多巴胺后AVP浓度的下降。给予氟哌啶醇（400微克/千克）后仍可见下降，但仅在注射多巴胺后20分钟有显著意义。给予纳洛酮（400微克/千克）后AVP浓度的变化无统计学意义。在水负荷大鼠中，脑室内微量注射多巴胺在1 - 25微克范围内产生剂量依赖性抗利尿作用。在这些动物中注射25微克多巴胺会使AVP浓度升高至1.8±0.51微单位/毫升，并使尿流量下降，通过以15微单位/分钟的速度输注血管加压素可大致匹配。氟哌啶醇可阻断对多巴胺的抗利尿反应。麻醉动物对多巴胺的反应取决于多种因素，包括神经垂体系统的初始活性。
